The background of the invention will be discussed in two parts:
1. Field of the Invention
This invention relates to filtering devices and more particularly to filtering devices having a microporous film membrane capable of selectively passing substances therethrough.
2. Description of the Prior Art
Filtering devices of an in-line type are useful in medical applications to protect the patients. Such filters are utilized to cleanse or filter the substance being transmitted, be it a fluid or a gas such as air.
Recently, materials capable of selectively passing certain substances have been developed, one such material being a microporous polypropylene film manufactured and sold under the trademark CELGARD by Celanese Plastics Company of Roselle, New Jersey. This microporous film while allowing the flow of gases, vapors and under certain conditions, liquids, is an effective barrier to bacteria, colloidal particles and other submicron materials. Being a polypropylene material, the film can be thermally fused to itself or other materials by conventional sealing techniques such as jaw-type sealing, impulse sealing, radio frequency and ultrasonic sealing.
Accordingly, it is an object of this invention to provide a new and improved filter device utilizing a microporous film membrane.
It is another object of this invention to provide a new and improved filter isolator device.
It is a further object of this invention to provide a new and improved filter device which is economical to produce and effective in operation.
It is still another object of this invention to provide a new and improved filter device having means for supporting a relatively thin membrane with means for dispersing injected fluid generally uniformly from the filtering surface.
It is still another object of this invention to provide a new and improved fabrication means for strengthening microporous polyethylene film for use as a filter device.